This invention relates, in general, to tuned integrated circuits and, in particular, to integrating an inductor into semiconductor technologies while maintaining a high quality factor and minimizing electromagnetic interference.
Since the development of tuned circuits, various types of energies such as electricity, light, and electromagnetism have been used to transmit various forms of stimuli, improving the quality of every day life. The stimuli transmitted from tuned circuits may be in the form of sound, e.g. phones and stereos, or in the form of light, e.g. television and data via a computer monitor. Such elements have enabled businesses as well as families to communicate with other counterparts across the globe conveniently and virtually without delay, resulting in closer bonds.
Tuned circuits have recently been introduced to semiconductor integration technologies. Though semiconductor technology has advanced in virtually every possible way, there is still difficulty when implementing tuned circuit technology. It has been very difficult to integrate large tuned circuit elements without sacrificing frequency extraction capabilities or quality factor (xe2x80x9cQ-factorxe2x80x9d).
An important tuned circuit element making the previously mentioned systems possible is the inductor. Inductors can have a respectively low frequency response, thus they can be utilized for low frequency extraction or limiting, depending on the configuration. Using inductors along with other circuit components make it possible to receive, extract, process, manipulate, and transmit information in the form of energies coving a broad spectrum of frequencies.
Recently, on-chip inductors have been introduced to the semiconductor fabrication process for integration. This process has experience some difficulties. Inductors are essentially a coil of wire or some electrically conductive material. Generally, as the size shrinks, so does their inherent inductance quality factor. Therefore, integrated inductors have respectively low inductances.
Including inductors in semiconductor technologies is also difficult due to the electromagnetic interference generated therein. The fields generated by one circuit element tends to interfere with the signals within other adjacent circuit elements. Additionally, inductors in semiconductor technology tend to couple fields to the substrate inducing Eddy currents within the substrate.
Therefore, a versatile system for utilizing inductors within an integrated circuit (xe2x80x9cICxe2x80x9d) without sacrificing the quality of adjacent circuit elements or coupling fields of the inductor to the substrate is now needed; providing cost-effective and efficient performance while overcoming the aforementioned limitations of conventional methods.
The present invention provides an integrated circuit comprising a first isolation layer having an inner and an outer surface, a second isolation layer having an inner and an outer surface, an inductor disposed between the inner surfaces of the first and second isolation layers, a first shield layer disposed upon the outer surface of the first isolation layer, and a second shield layer disposed upon the outer surface of the second isolation layer and adapted to couple to the first shield layer about an outer perimeter of the first and second isolation layers.
The present invention also provides a device for reducing electromagnetic interference within an integrated circuit having an inductor, comprising an inductor layer having conductive elements about its perimeter, first and second isolation layers disposed upon on opposite sides of the inductor layer and having conductive elements about their perimeters, and first and second shield layers surrounding the first and second isolation layers, respectively, and coupled together by the conductive elements of the isolation and inductor layers.
The present invention further provides a method of shielding electromagnetic interference of an inductor within a semiconductor component, comprising the steps of providing an inductor, providing first and second isolation layers disposed upon on opposite sides of the inductor, having conductive elements about their perimeters, and providing first and second shield layers surrounding the first and second isolation layers, respectively, and coupled together by the conductive elements of the isolation layers.